1. Technical Field
This disclosure relates to mobile communication devices and to energy saving approaches for minimizing the energy consumed by such devices.
2. Description of Related Art
The surging popularity of mobile devices has created an entirely new software market for mobile applications. Many mobile phone applications rely on network communications and data processing to provide automated and personalized services, such as context or location based services. Given the very low entry barrier for mobile application development, there are many application developers who focus primarily on application functionality.
But battery life of a mobile phone can be a critical bottleneck to the end-user experience of using an application. For example, a Nokia N95 phone battery has been reported to have dozens of hours of standby time, but when used for context monitoring by sensing audio, GPS and Wi-Fi access points, the battery has been reported to drain in 4 hours. As mobile applications become pervasive, the limited battery problem may only get worse as multiple applications may in fact access the same hardware independently at different time intervals.
At each stage of a mobile application design and operation, the application developer has a wide range of options to trade-off battery life of a mobile phone for other important metrics. For instance, many mobile devices provide multiple different approaches for interfacing with a computer network such as the Internet. These may include, for example, a Wi-Fi interface and a cellular interface. Similarly, there may be choices over whether data computations are performed within or outside of the mobile device. Each of these choices may consume different amounts of energy. Unfortunately, writing application programs that make the most energy-efficient choice can be costly and very difficult.